Add audio announcement option to app_page

As described in the CHANGES file:
* MeetMe has a new option 'G' to play an announcement before joining a
  conference.
* Page has a new option 'A(x)' which will playback an announcement 
  simultaneously to all paged phones (and optionally excluding the caller's one 
  using the new option 'n') before the call is bridged.

To add the new option to meetme, the conference flag options had to be extended 
to 64 bits.

(closes issue #14365)
Reported by: dferrer
Patches:
      page_announce.patch uploaded by dferrer (license 525)
      modified by me

Review: https://reviewboard.asterisk.org/r/188/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@234173 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/app.c

@@ -1836,10 +1836,6 @@ int ast_app_parse_options(const struct ast_app_option *options, struct ast_flags
 	return res;
 }
 
-/* the following function will probably only be used in app_dial, until app_dial is reorganized to
-   better handle the large number of options it provides. After it is, you need to get rid of this variant 
-   -- unless, of course, someone else digs up some use for large flag fields. */
-
 int ast_app_parse_options64(const struct ast_app_option *options, struct ast_flags64 *flags, char **args, char *optstr)
 {
 	char *s, *arg;